If you are trying to convert your 16×2 display to I2C, you’ve probably googled and found many resources on the Internet. But if you happen to have a MGD1602B series LCD module, this may be your lucky day, because I’ve already designed a board in Eagle Cad for this purpose. Keep reading and download converter schematic and board. All for free, as (almost) always. Bonus: Eagle Cad library (.lbr) for this LCD module.
First of all, please note that I didn’t invent anything new except for the board itself that was designed for this specific LCD module.
The circuit was stolen from Mario_H’s page. In this page you will also find an Arduino library to drive the LCD via I2C.
MGD1602B Series LCD module
This generic 16×2 module has the following pinout. Please always verify if your LCD match this one, there are a lot of line displays out there from different manufacturers and specs totally different.
The + and – are pins 15 and 16 respectively.
In this peculiar LCD pins 15 and 16 are not following the linear order of the rest of the pins from 1 to 14!
And here is the MGD1602B-NS(W)-BBS BACK AZUL Datasheet, just in case.
Arduino Duemilanove connection
SDA (inner board pin, not being 5v) -> A4
SCL (outer board pin, not being ground) -> A5
Testing code (using LiquidCrystal_I2C library)
Note that the address is 0x38 (all 3 address pins grounded).